MB100 development

[husaberg]

Husa - has Wob managed to get John H to bring the NSR motor south ? i know John slightly and could collect and bring over at labour weekend.
You know as much as i do, Mike is having similar issues, but if it does arrive in CHCH that would be awesome, i am over the weekend of the 12th though

Well if Wob-John H can get it to Palmy.
Then we might be able to fit it in the truck coming south for the BOB. then you can drive over and help for the day and maybe consume a little!!!
This is the longest build; no wait, Ivan........:killingme
I think it was supposed to go direct to CHCH with some guy and the Ivan that is a low blow..............probably deserve it though....

nah mine is an LC now. But I did see those 125 kits and think would be an easy start.
i was meaning the honda stuff bt yes it would appear to be the way to go for an easy build. But then again it still has to be modded a lot in the cases to fit the RS chassis anyway i was hoping to avoid that with the NSR engine.

you should of done the work your self and get job satisfaction from it.
Yes i should have but it likely still wouldn't be finished anyway:innocent:

[Bert]

I think it was supposed to go direct to CHCH with some guy and the Ivan that is a low blow..............probably deserve it though....

I think you read my post wrong... but nevermind.

Third longest bucket build.... Ivan, me then you.
Nope; wrong again... I've raced and destroyed mine twice so the list goes; Ivan, husa then me...... :lol:

[Kickaha]

Yes i should have but it likely still wouldn't be finished anyway:innocent:
Saves you the embarrassment of being thrashed by the Mighty GN at the BOB I guess

[F5 Dave]

Diesel and DC had mounted MB engines with std cases by compromising forward placement without too much issue, also frame spar mounts. Carb placement difficult, Diesel did rose joints, but DC had large engine thus 24mm carb, seemed to fit.

[husaberg]

Well if Wob-John H can get it to Palmy.
Then we might be able to fit it in the truck coming south for the BOB. then you can drive over and help for the day and maybe consume a little!!!
This is the longest build; no wait, Ivan........:killingme


I think you read my post wrong... but nevermind.

Third longest bucket build.... Ivan, me then you.
Nope; wrong again... I've raced and destroyed mine twice so the list goes; Ivan, husa then me...... :lol:

Yeah i did, i just seen me in the same sentence as the "Ivan":2thumbsup.
After i seen that i was too busy running about "bitch slapping" myself to hear anything else........
My last update was Wob was giving it to a guy to run up to Auckland, and then i thought a kart guy to go direct i thought to CHCH. ( i will pm him again)
One things for certain though Husaberg is totally 100% off the piss for the foreseeable future i am afraid. :weep:


Saves you the embarrassment of being thrashed by the Mighty GN at the BOB I guess

Your right. One of us would have to commit Harri Kari (but my money would still be on the GN ended up disemboweled with or without me there);)


Diesel and DC had mounted MB engines with std cases by compromising forward placement without too much issue, also frame spar mounts. Carb placement difficult, Diesel did rose joints, but DC had large engine thus 24mm carb, seemed to fit.

Say what with the rose joints? the mounts? confused........
Mine is already sans the front mounts from it's previous existence as a YZ250 powered F3

[F5 Dave]

Yeah i did, i just seen me in the same sentence as the "Ivan":2thumbsup.
After i seen that i was too busy running about "bitch slapping" myself to hear anything else........
My last update was Wob was giving it to a guy to run up to Auckland, and then i thought a kart guy to go direct i thought to CHCH. ( i will pm him again)
One things for certain though Husaberg is totally 100% off the piss for the foreseeable future i am afraid. :weep:



Your right. One of us would have to commit Harri Kari (but my money would still be on the GN ended up disemboweled with or without me there);)



Say what with the rose joints? the mounts? confused........
Mine is already sans the front mounts from it's previous existence as a YZ250 powered F3didnt like the rose joints on shock idea. No front mount, need a head mount.

[husaberg]

didnt like the rose joints on shock idea. No front mount, need a head mount.

I can't picture what you mean. i was intending to add the front struts back on like it was originally.
Has anyone got pics of diesels or DC's.

[F5 Dave]

Yes but not here, at werk if I remember . The shock was on an angle which was a bodge too far I thought and relied on rose joint movement to correct through stroke. Don't use the front mounts on an MB engine, they fracture as cases too thin, they aren't used as mounts. Yeah I know, but you have been warned.

I welded ally ally mounts near head and use plates on them so can easily change for different head heights.

[husaberg]

Yes but not here, at werk if I remember . The shock was on an angle which was a bodge too far I thought and relied on rose joint movement to correct through stroke. Don't use the front mounts on an MB engine, they fracture as cases too thin, they aren't used as mounts. Yeah I know, but you have been warned.

I welded ally ally mounts near head and use plates on them so can easily change for different head heights.

OK i think i understand what you mean about the Shock but the pics would be handy.

Yeah I remember the warning about the front mounts no worries. But i was going to use them for the NSR.
The frame has short triangular mounts in place already (not sure if they show in the pic or not.)

I guess i still have a 6 speed MB5 gearbox as well so that's a start i guess.

So i guess i might be looking for a MB100 engine soon. WHY.......

[Bert]

OK i think i understand what you mean about the Shock but the pics would be handy.

Yeah I remember the warning about the front mounts no worries. But i was going to use them for the NSR.
The frame has short triangular mounts in place already (not sure if they show in the pic or not.)

I guess i still have a 6 speed MB5 gearbox as well so that's a start i guess.

So i guess i might be looking for a MB100 engine soon. WHY.......

Yea WHY. The NSR is in the country, destroke it and add your fancy cylinders. Job done.

[speedpro]

I have relocated the front engine mounts on my RS from on the end of the arms going down to being welded directly to the spar as per your first pic of the chassis. Then placing an alloy plate under new head studs like I have all you need is a little angle bracket on each side with a bolt through the engine mount on each side. I have retained the rubber engine mount things.

[husaberg]

Yea WHY. The NSR is in the country, destroke it and add your fancy cylinders. Job done.


Had you considered using something like this Below.
The carb seems tucked out of the way it has one of those water pumps Frits seem to like. It also has one of those Power valve thingies that seem to spread the power out a wee bit. It has a 6 speed gearbox was built in the last 20 years and most importantly is a Honda. I hear there is one at Tauranga.
It needs a bit of work mind you the Crank pokes to far up and to far down as well, The piston seems a little er...big as well. Oh well it can be fixed i guess.
As the RS frames seem to be a bit thin on the ground i am hoping it will fit in one of these. it should just about cram in there with a little persuasion

It will be 2 years in 2 months time..............
I ain't get any younger.

[Grumph]

It will be 2 years in 2 months time..............
I ain't get any younger.

None of us are....I though I'd seen mention of the boy riding it eventually.

On that basis you've got plenty of time - and can give up the diet too.

[F5 Dave]

Ok here's Neil's bike, hope he doesn't mind me posting it, but he's changed to a RG engine anyhoo.
Shock was cocked over to give carb clearance, but 24mm carb much smaller if you make a 125.


Early mockup of mine, threaded ally plates welded near shock mount, then steel plates (head bolt hole not drilled yet). Can be difficult to feed the bolt through depending on how far down it is.

[husaberg]

Ok here's Neil's bike, hope he doesn't mind me posting it, but he's changed to a RG engine anyhoo.
Shock was cocked over to give carb clearance, but 24mm carb much smaller if you make a 125.


Early mockup of mine, threaded ally plates welded near shock mount, then steel plates (head bolt hole not drilled yet). Can be difficult to feed the bolt through depending on how far down it is.

Thanks for the pics i'm totally With ya now re the rose joint/shock to the side. looks like DP bike has a long intake as well.
gee Life would be so so much simpler with a NX4.

Life was hard enough on the H100/MB5 with the TZR carb as the coil had to be removed and then the screws on the carb top needle changes were a bitch. Yet with an old VM mikuni it was sure a doddle.

quick easy access to carb for me is a priority anyway.

Anyway after figuring out how much i had actually spent already, i might be kinda stuck with the NSR engine:shit:

[husaberg]

I found the pic of DP's RGV100.http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=288774&d=1382238744
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=288775&d=1382238746

[husaberg]

Anyone seen this crazy Hp for the carb size optimistic dyno.
http://www.kiwibiker.co.nz/forums/showthread.php/162037-UK-bucket-owner-Honda-H100-or-MB100-tuning-advice?highlight=mb100+h100

http://www.bikechatforums.com/viewtopic.php?t=279145

http://i212.photobucket.com/albums/cc108/CB1Rocket/h100%20destruction/DSCI0059_zps5c2c64ce.jpg

[Grumph]

Ha - and you were pushing the Athena kit at me....

That HP is feasible on that carb - but very hard fought for and very peaky. Yes, a bigger carb would give more everywhere IMO.

Couple of things - If that bore is nikasil, can you hone it satisfactorily ? I thought diamond hone and then back etch for oil retention ?
And no mention of ignition timing either....

[husaberg]

Ha - and you were pushing the Athena kit at me....

That HP is feasible on that carb - but very hard fought for and very peaky. Yes, a bigger carb would give more everywhere IMO.

Couple of things - If that bore is nikasil, can you hone it satisfactorily ? I thought diamond hone and then back etch for oil retention ?
And no mention of ignition timing either....

no mention of it going back to the tuner either where it should go first.
I can't understand why anyone would leave the 18mm carb on.
I was actually wondering if they are really plated.........oh yes they are.

Oh..... one does not push anything on you Greg.

this is his build thread looks like he jetted it himself............
http://www.bikechatforums.com/viewtopic.php?t=253852&postdays=0&postorder=asc&start=0

engine looks like it was tuned in Germany.
Cylinder Head is like our H100 less fining than fish fillet and open road.
pipe looks ugly too.

[F5 Dave]

You have to be Neil to be comfortable on that bike but he rides it well and I have a soft spot for it as it motivated me to finish mine (in time for Taupo)

[ryd_or_die_278]

hey hope I don't get it the shit for tagging along in this post, but I read a lot about the manifold/ reed cage / carburettor mods for the MB100 in this post and want to know if someone could give me some guidelines, so I got given this bike when it was runnin a sak of shet think its about an 80' and tryd to tune it beter but some1 decided to cut of the overflow from the carb and change the float height before i got it :angry:, I dremeled the shit out of the carb/manifold and tinkerd wit carb needle n float nd got it runin a lot beter, but still runnin shit 2 me, so i know when this bike gets a proper fuel/air delivery its gona be awsum

soooo... i want to get a RD350 intake and reed cage, which year parts should i look for? and does andbody have any good sources? i understand i wil have to do couple mods to attatch these, also what is a good carb that will strap str8 in 2 the RD350 intake?

i know this bike has potential! and i love working on two strokes;)

again sori if i shudnt have posted here, :wacko:
any help would be much appreciated , thankz

[koba]

I dremeled the shit out of the carb

Really?

Got any pictures?

[F5 Dave]

Now that RD350s are classic its getting harder. But any yam of the era you can cut off the back of the barrel reed area and weld to back of hogged out Honda inlet and use the manifold and carb. Ie dt175 etc.

[TZ350]

290006

I found the pic of DP's RGV100.

I am sure I have seen those pictures before, just can't think where .... :scratch:

[husaberg]

I am sure I have seen those pictures before, just can't think where .... :scratch:

really......... i guess they do look a little like your ones, same bike i guess, so you'd expect that though:msn-wink:

[TZ350]

pictures have the same name too .... :laugh::laugh:

[husaberg]

pictures have the same name too .... :laugh::laugh:

What are the chances of that:eek5:
I think mine was bigger though:2thumbsup

[Kickaha]

I think mine was bigger though:2thumbsup
That not what your girlfriend said

[husaberg]

that not what your girlfriend said

your right she said "i am the biggest"............

[datfreak]

Hi guys, ive been slow to report (im the guy in oz with the h100a that I want to keep as a pipey street bike) but had some personal problems putting my hobbies on hold for a bit...

Anyways - progress report.
I've received my 2004 cr85 reed block, 28mm carby, throtle twist w cable.

ive started grinding out the reed block entry of the h100 and with a 12mm plate, I think the reed block, inlet and carby should mount up nicely.

I'm curious how to increase the compression ratio - removing the head gasket leaves very little piston-head gap. and doesn't up the CR enough.
And ideas? I was thinking about a thicker head gasket (copper?) and machining the head alot into the smaller squish region. Its hard to figure clearance with the piston dome and the head.

Oh by the way i found another 2 stroke tuning manaul online - see (and save):
http://www.amrca.com/tech/tuners.pdf

its different then grahams bell's book and more information is always handy :)

[datfreak]

soooo... i want to get a RD350 intake and reed cage, which year parts should i look for? and does andbody have any good sources? i understand i wil have to do couple mods to attatch these, also what is a good carb that will strap str8 in 2 the RD350 intake?

i know this bike has potential! and i love working on two strokes;)

again sori if i shudnt have posted here, :wacko:
any help would be much appreciated , thankz


reed and carb from cr85 can be made to fit. The reed bolts have the same pattern, but the h100 barell must be opened up alot.

290341290340

[F5 Dave]

. . .. Its hard to figure clearance with the piston dome and the head.
...
Bit of solder down the spark hole works fine for me.

Close it up to 0.8-1mm then measure the volume. I've skimed the head till it has no real step from the bottom fin, then created a chamber in that. Easy to get 16:1, but that's now water cooled & on Av gas. Aim for 14:1 if you run say 96 gas.

Aircooled can run with no gasket & ring of loctite master gasket. or machine a groove & fit an o-ring, think mine is 2.4mm maybe V140 or 142 perhaps. Viton material. Need to make the groove pretty wide, but there are charts for that.

[husaberg]

When i did mine i used replicated the air cooled CR80 intake and cut outs with no brake troughs or spacer plates.
I used the Air cooled reed though and a RD250 intake with the wings trimmed.
you reed looks maybe a little deeper(longer) plus the intake seem straight is it?
I didn't take any pics but if Hilleye is still around he has my cylinder. Maybe he could.

this is the air cooled intake which i replicated (note the reed screw cut outs)
but i see that is not how Mike done his re the single port and his has more HP.

[koba]

When i did mine i used replicated the air cooled CR80 intake and cut outs with no brake troughs or spacer plates.
I used the Air cooled reed though and a RD250 intake with the wings trimmed.
you reed looks maybe a little deeper(longer) plus the intake seem straight is it?
I didn't take any pics but if Hilleye is still around he has my cylinder. Maybe he could.

this is the air cooled intake which i replicated (note the reed screw cut outs)
but i see that is not how Mike done his re the single port and his has more HP.

Gosh that's a big hole!
I've gone the other way and put a port on each side of the standard port.
Seems to work great and has to be easier on the piston.

[husaberg]

Gosh that's a big hole!
I've gone the other way and put a port on each side of the standard port.
Seems to work great and has to be easier on the piston.
looking at the pic i would say mine was actually wider.
Never actually had an issue and was surprised when i saw Mikes was a triple port. but i guess his was more area and the single would lose some area esp with the reed bars and outer area.
I tried to find the port map, it is somewhere, but it was within the "Bell specs" for width.
The pic is a std Cr80 ac which was around 49mm bore.
I are still gutted i never got around to running it with a decent size carb.
the CR80ac had a huge bridge port ex, with eyebrow windows and a tiny crankcase and huge transfers std.
same stud patern as the MB100 as well, only it has the MB50 stroke.

[koba]

looking at the pic i would say mine was actually wider.
Never actually had an issue and was surprised when i saw Mikes was a triple port. but i guess his was more area and the single would lose some area esp with the reed bars and outer area.
I tried to find the port map, it is somewhere, but it was within the "Bell specs" for width.
The pic is a std Cr80 ac which was around 49mm bore.
I are still gutted i never got around to running it with a decent size carb.
the CR80ac had a huge bridge port ex, with eyebrow windows and a tiny crankcase and huge transfers std.
same stud patern as the MB100 as well, only it has the MB50 stroke.

True, competition heritage makes it a no for buckets but would possibly be really good on a road bike if it's got enough in it to adapt to 100 stroke, bridged exhaust and all.

[datfreak]

Guys - as before thankyou for this info.
The idea of using solder to check dome/head gap is very clever. thinking of sanding the head down with w&d paper on a glass sheet then (very carefully!) reshaping the head outer rim with ----i will not do anything to a two stoke head with a dremel------so maybe, ill wrap the piston in sandpaper also and "spin it" in the head until the squish and the CC's were correct.
- i was going for about 13-14:1 C.R and using 98 fuel and a synth 2 stroke oil.

"bell rules" say I should have 35mm ish wide exhaust port and inlet - but im curious to this 3 window inlet idea.
Any idea on what a safe divider width would be? Its on the cold side of the motor so i think i should get away with a thin one :)
Just having a look and those side windows will be VERY close to the transfer runners.


EDIT : if I go with a 3 window design for the inlet, the side windows will go around the bore enough to be "open" even @ bdc (due to the shape of bottom of the pistons skirt), does this matter at all?



Here is a pic of the h100 barrel with alot of alloy(and steel) removed to fit the cr85 reed block. - this is still a work in progress, as i still have to take at least another 5mm off the one side and cut a 12mm piece of alloy plate for a spacer. oh and here is a inlet BEFORE pic
290349290350

[husaberg]

repeat after me i will not do anything to a two stoke head with a dremel...... i will not do anything to a two stoke head with a dremel.

[speedpro]

Something like this.
Make sure the side of the reed petals don't scrape on the side of the cylinder inlet as they open and use devcon or similar to form a nozzle from the reed stops top and bottom into the ports. You don't want any sudden changes in cross section.

[Grumph]

i like the triple inlet setup. If i was to do another MB barrel that's how I'd go. I've had good results with the single port but it's eventually not big enough but too big for safety...Looking at the side ports on the triple, it may even be possible to squeeze in a couple of Boyesen ports through into the rear transfers. That's probably only possible as a 100 as when it's big bored there is NO room there...
With the better piston support of the triple, You could use a port in the piston too - these work really well to lengthen small end life but with the big single port piston life is too short.

[koba]

i like the triple inlet setup. If i was to do another MB barrel that's how I'd go. I've had good results with the single port but it's eventually not big enough but too big for safety...Looking at the side ports on the triple, it may even be possible to squeeze in a couple of Boyesen ports through into the rear transfers. That's probably only possible as a 100 as when it's big bored there is NO room there...
With the better piston support of the triple, You could use a port in the piston too - these work really well to lengthen small end life but with the big single port piston life is too short.

You can fit some tiny boysen ports in there, I think the area is possibly better employed making the side ports of the triple better though as the stud spacing is quite restrictive.

[koba]

Here is a pic of the h100 barrel with alot of alloy(and steel) removed to fit the cr85 reed block. - this is still a work in progress, as i still have to take at least another 5mm off the one side and cut a 12mm piece of alloy plate for a spacer. oh and here is a inlet BEFORE pic
290349290350

Cool, looking good.
As part of that work in progress make sure you give it a nice radius from the roof of the inlet up in to the boost port.

[speedpro]

Make sure the end of the reed stops and the reeds themselves don't obscure the boost port.

[F5 Dave]

Which is why a spacer or better yet a new bit tack welded on is usually the go. I just ran ports either side of the main about the same time as I mentioned it to Mike he was apparently already but presumably Pete S had been going this way. It just seemed logical & easy to get way more area than you need from what your carb will flow.

I'm cheating now as I don't have an inlet port in the barrel. . .but its more than you could achieve with a dremel.

oh yeah, forget the glass & sandpaper for head. Get someone with a lathe to take a swathe off the face & cut an old piston in half so they can do the chamber to the right angle & di (+ a smidge). Then make a guess at a bowl shape. From there you measure with fluid & have to recut a couple of times.

trying to do the above by hand will result in you going crazy with boredom, but mainly, you might get it flat - but won't give you much hope of it being square once you bolt it up.

[speedpro]

couple more. In 0988 you can also see the adaptor plate and the spacer that the pretty big 6 petal reed mounts to.

[datfreak]

thanks guys the info-- and the pics are art! just beautiful

oh and i didnt think about the reed pedal covering the boost port , it is maybe 8-10mm past the reed cage tip.

[datfreak]

290461290462

The cr85 carb and inlet pipe mounted.
no I havn't done the porting yet but I couldnt resist to see it together :) . Started easily but would not rev too high (? too small of jet? it has 125 mains)
The inlet pipe is slightly bent, and points the carb west - it doesn't get the carb level but close enough.

The 12mm spacer plate was more work then expected - honda has very tight spacing with the reed screws to outer edge. Hours of filing and grinding.

The other pic is the remains of the oil pump. it is my attempt to delete the pump. I was going to make up a plate to seal it, but i found it easier to cut up the pump and use that. I think i will work a treat.

re: inlet porting - I was thinking of doing a 2 port - ie taking the existing inlet port to one side to a total of 33-35mm , then have a bridge on the other side and a 20-25mm port. but maybe this will be too hard on the piston. So may go with the 3 port alike to what you guys have done.

[koba]

290461290462
Started easily but would not rev too high (? too small of jet? it has 125 mains)

To small, or too big.

What pipe do you have?

[F5 Dave]

No body can predict what jet size you need, but a word of caution. Spend some time finding the right size or slightly too big. These bikes can be super reliable, but too lean of a jet will seize any 2 stroke solid. Heaps of jetting articles on web. Small steps.

[husaberg]

Which is why a spacer or better yet a new bit tack welded on is usually the go.


No body can predict what jet size you need, but a word of caution. Spend some time finding the right size or slightly too big. These bikes can be super reliable, but too lean of a jet will seize any 2 stroke solid. Heaps of jetting articles on web. Small steps.
When i mentioned the the reed at the start it sure looks like the later CR85 reed is deeper looking the Old aircooled reed was very short hence why no spacer for me.
I seen a real could jetting from scratch article the other day i will see if i can regoogle it onto the web.Its the neatest one i have seen.
http://books.google.co.nz/books?id=J7tQp2LtsYIC&pg=PA61&lpg=PA61&dq=Carbs+are+complex+because+of+their+overlapping+ kevin+cameron&source=bl&ots=qdU5EuhyxB&sig=ypUCl-6ePjegQmrw1WZLeuRB4Ko&hl=en&sa=X&ei=QpeaUpyhKYjoiAegyIHIAw&redir_esc=y#v=onepage&q=Carbs%20are%20complex%20because%20of%20their%20o verlapping%20kevin%20cameron&f=false

I do remmber why i never used the CR inlet thopugh because the angle was wrong even with the Downdraft TZR carb.
Make sure the Keihin isn't to steep that the float level is off and fuel comes out.
I used a RD250 inlet it was a simple job to fit. redrill two holes file the other two.

PS put a filter on it.

[datfreak]

hi guys -
I'm not too worried about the jetting as yet - ill do the porting then sort the pipe THEN re-jet it . I just wanted to hear her run again.


The carb is on a bit of a angle - but is that a prob? Under throttle (and the bikes nose comes up) the angle wouldnt be too much.... I might look for a RD inlet just to be sure.

I'm unsure on which pipe as yet i was thinking of butchering a rv125 aprilla expansion chamber - or using a premade one like this one
http://www.josdijkman.nl/shop/index.php?act=viewProd&productId=4468

I was recommended tthe above pipe by a euro pipe guru see his website here:
http://honda80ccracing.weebly.com/

Id really like a stainless "welded" -like the arrow branded ones- pipe but i think it will blow the budget.

ill update when ive got some porting done.
cheers

[datfreak]

290765290766290764

some porting done ..After making one inlet side larger, I tried to copy it on the otherside and......... went thru into the barrel stud channel.

Would have looked ok if I hadn't screwed that up. Maybe the bridges are a little skinny (esp when I take the edge off them) - i have seen a few like this on online porting pics - piston life may not be the best :)


I did bell rules with the inlet and exhaust port ., ex width ,floor height, piston bottom to top of inlet port
-- and if I did the maths correctly, increased ex timing to 194 degrees. Which isn't too wild, but I can take more off later.

I need to do alot of smoothing, but this can wait until I fix the hole.

looking into devcon now - but seems it is only sold in big amounts.. Is there a another brand "metal fill" epoxy that is good enough? Something I can buy from suercheap/repco?

[Grumph]

Instead of Devcon, it may be safer to bore the stud hole say 1mm bigger over a short distance and press in a piece of thin wall tube.
From memory, the stud holes have a generous clearance to the stud so it should be possible to use 1mm wall tube.

This is a common fix for cracked 60's triumph heads....

[speedpro]

I simply would not worry about it. It's all sealed top and bottom so who cares.

[Ocean1]

Instead of Devcon, it may be safer to bore the stud hole say 1mm bigger over a short distance and press in a piece of thin wall tube.
From memory, the stud holes have a generous clearance to the stud so it should be possible to use 1mm wall tube.

This is a common fix for cracked 60's triumph heads....

I used to port 1275 mini heads completely ignoring a pair of pushrod holes, which I'd ream oversize beforehand to take 5/8" hydraulic tube. I'd break into the holes by a good 5-6mm but with the tubes pressed lightly in with Loctite the ports flowed better than the traditional conservative shape.

I did the same with some stud holes once, machined up a tube with a top-hat to fit a register in the hole to feed the compression into the head. Worked OK.

[F5 Dave]

I agree with speedpoo. But JB weld is pretty good and should find on ebay in packs of a few s,mall tubes.

[datfreak]

thanks guys for your ideas... I like the idea with the thin walled tube, ill have to see it iI can get some locally.
Otherwise ill give the jb weld a go( i did a search and a local electronics dealer stocks it - Jaycar).

And its true, speedpro's "do nothing" would be fine but im being anal retentive and want a flat smooth surface for flow ------ i know it would probably makes no difference, but i stuffed up and want to fix it... ( i do change my mind alot-- maybe tomorrow do nothing will sound like a very good idea)

edit: If i do the "do nothing" approach, then i could open that side port even more (like the otherside),making the hole even bigger..... and the worst thing that could happen is that the head stud maybe in the side of the inlet as a ridge... this may effect flow but this would be countered by the port, being bigger and having a otherwise better line... decisions

[datfreak]

291270291271

Hi, I did the alloy tube idea to fix the hole, it worked great. As the pic, the wall isn't perfectly smooth but close enough.

Also , see the other pic - One of the foot pegs has snapped off, so ive got the x member off for welding. The alloy rim is a high lip 18" D.I.D, I'll be putting these on when I get new spokes (stainless unless they are too expensive, if so ill get chromed thai ones).

Just took it for a little run, and had to move the needle up to the highest point to remove mid range bog down, so I may have to go up a main jet size.

And she has now a lot more grunt - front comes up nicely.. Kinda feels like a older cr125 that I had before - just the h100 has terrible brakes and suspension :) Will be great when I get a better exhaust and tune the carb,.

I was going to keep the original drum front as it is only going to be a street bike but now after riding it, maybe a disc front end is a good idea.


I'm surprised how easy it is to ride, I expected it to be more pipey(like cammie on a 4 stroke)- but it feels quite flexible.

This bike has no tacho or tacho drive, so is there a tacho that runs off the cdi OR would I be better off getting a h100 side cover that has the drive?

EDIT: ok there seems to be a few universal tachos that should run from cdi but they use 12v - is there a 12v conversion for the h100? like the yamaha one http://www.youtube.com/watch?v=ljDFwVgvELI

[koba]

291270291271

EDIT: ok there seems to be a few universal tachos that should run from cdi but they use 12v - is there a 12v conversion for the h100? like the yamaha one http://www.youtube.com/watch?v=ljDFwVgvELI

There are heaps of options, for a rod bike the best bet would be to get a (Much) lighter Stator/Rotor setup of something else.

The standard MB/H one is shit for performance work.

As racers we don't have to worry about lights and indicators but I'm sure there is plenty out there.

For the tacho you could run a small battery for tuning work, when you need to know the revs, after that just unhook it all and get to know the bike.

[datfreak]

....best bet would be to get a (Much) lighter Stator/Rotor setup of something else.
.

So Im back to searching for more cr80/85 parts ?I should buy a bent cr for parts ;) Do any year flywheel and ignition fit? does the cr stator coil fit on the h100 stator plate (as the cr on is a 2 vs h00 3 hole)?
\I'm on holidays now (yay!) so I can do a build thread and stop hasselling you chaps in the mb100 dev one - but saying that, your knowledge and 2 stroke experiences have been so very helpful.

[koba]

So Im back to searching for more cr80/85 parts ?I should buy a bent cr for parts ;) Do any year flywheel and ignition fit? does the cr stator coil fit on the h100 stator plate (as the cr on is a 2 vs h00 3 hole)?
\I'm on holidays now (yay!) so I can do a build thread and stop hasselling you chaps in the mb100 dev one - but saying that, your knowledge and 2 stroke experiences have been so very helpful.

Older CR 80's bolt on.
Will try find a link.

No good for a road bike if you want lights though, really you will need to shop around for something that has lighting coils too, if it is already made for 12v just graft the whole lot on.

[speedpro]

I've made mistakes with what I'm using but pretty sure a CRF150 generator and rotor fits with an adaptor plate. Use the whole rectifier/regulator and capacitor and you end up with 12V supply and trigger for a CDI. The rotor is a direct bolt on to the MB/H crankshaft.

[F5 Dave]

I keep telling you that is not crf. They have inside out arrangements. CR125 or 250 03 ish. 40w of power. Suit a baby light at most. Getting harder to find. Can get 50w after mkt but $+

[datfreak]

anyone tried
http://www.mh-aerotools.de/airfoils/javapipe_en.htm

?
(you have to install java for it to work).
Is the sizes correct ? pity the exhaust size only goes to 1000 m2. Curious to what you guys think..( Im still sussing out a nice exhaust for my h100)

[F5 Dave]

Are you intending to cut and weld them? I can send you pdfs of cones that should do the trick

[datfreak]

6 months later and i thought I'd ask more questions! -yes life got in the way again.

Does the mb5 engine covers fit the h100? ie will the mb5 clutch cover with tacho drive fit on my h100? looking on ebay they LOOK to fit with both patterns appearing the same.


Ive put a kawasaki kh100 gauges on the h100, and the speedo is working but i want the tacho to come alive - i m hoping the mb5 and tacho cable will enable this to happen.

and how does a rg250 expansion chamber go on a modded h100? ok or would I better off welding my own chambers?

btw if someone has a mb and h100 clutch cover for sale with tacho drive pls let me know.

[husaberg]

Does the mb5 engine covers fit the h100? ie will the mb5 clutch cover with tacho drive fit on my h100? looking on ebay they LOOK to fit with both patterns appearing the same. .

yip.............

[koba]

RG250 pipe is a start, it will get you going.

Far better can be made with Bell's math, far better again with modern understanding.

I've run an RGV250 and an RG400 pipe on mine, both worked OK but were considered a starting point, my first hombuilt one was less than 1/2 the weight and made a good deal more power.

[speedpro]

A good pipe made from .8mm MS probably only weighs as much as the carbon inside an old RG pipe.

[datfreak]

yip.............

thanks - there is a few tach right covers off mb5's on ebay US, ill suss one out.

advise re: the chamber is kinda what I thought - I'm ok with the work making one but my welding skills are lacking (and lack of roller)so maybe a rg one might be the go
cheers

[husaberg]

thanks - there is a few tach right covers off mb5's on ebay US, ill suss one out.

advise re: the chamber is kinda what I thought - I'm ok with the work making one but my welding skills are lacking (and lack of roller)so maybe a rg one might be the go
cheers

if you can try for the tacho as well I fitted the std MB5 ones drive unit into a std Honda round binnacle from a XL100s.
I am not sure what ratio they are but then again, any would do just set the redline with a vivid after checking it with a electronic one.

[datfreak]

I know its the wrong place to put this-- but im in qld australia and wont be visiting for a while and the mb100 for $50 is a bargain see:
http://www.trademe.co.nz/motors/motorbikes/parts-for-sale/frames/auction-757399362.htm
hopefully someone here can buy and use this

[F5 Dave]

Would be if it goes for that, but it won't that's just the start price.

[flyingbrick]

Sneeky thread bump.. pickup my own mb100 tomorrow. Thanks everyone for all the info in here! Happy for others to dump more links to other stuff worth reading.

[F5 Dave]

Um, well the ESE thread will keep you reading for a few nights.

[flyingbrick]

Hi everyone :-D

My bone stock mb100 tops out juuuuust under 100kph and i'd like to lose a few resr teeth to speed things up a little. Does anyone have the specs for the rear sprocket? Eg pcd, chain pitch, hole size etx

Thanks in advance, my local honda guy couldnt help and i dont want to pull bike to bits just yet (im not good at putting things back together, lol)

[husaberg]

Hi everyone :-D

My bone stock mb100 tops out juuuuust under 100kph and i'd like to lose a few resr teeth to speed things up a little. Does anyone have the specs for the rear sprocket? Eg pcd, chain pitch, hole size etx

Thanks in advance, my local honda guy couldnt help and i dont want to pull bike to bits just yet (im not good at putting things back together, lol)
JT or Metal gear
http://www.jtsprockets.com/

[husaberg]

look under H100A
https://i.ytimg.com/vi/l-7Zng6H0LY/maxresdefault.jpg
15,35
http://www.jtsprockets.com/catalogue/model/103/

if you are street riding it buy a 57mm big bore kit and a early CR80 air cooled for the trans.

[F5 Dave]

100kph is probably about it - if you gear up the wind or a hill will make 4th gear too tall.

[flyingbrick]

Thanks you two :-D.

Feels like it could go way faster than 100 but its reving past its peak power. Could be wrong as im a total novice! Thanks for links above. Found bike there, h100a etc. Looks like all they have is one toth less out back or +3% top speed. Will give it a hoon. Keen for big bore kit and more gears! But also dont want to tuen it into a huge project just yet (i have a bad history with projects)

Thanks again

[husaberg]

AS Dave said for a STD bike 110 would be it.
its not the gearing its the lack of ability to rev higher.
They are simple to tune and easy to work on.
Pipe and carb and a few simple bits would have you up to 140km on std gearing.
But they have shit brakes and tyres. It depends what you want to do.
it would be cheaper to buy a faster bike but wheres the fun in that.

[flyingbrick]

Exactly. Thanks all.

[flyingbrick]

There's some gt125 wheels, forks and brakes on tm. Anyone ever fitted these forks and wheels to an mb100? Decent reduction in weight?

I love the look of em

[husaberg]

There's some gt125 wheels, forks and brakes on tm. Anyone ever fitted these forks and wheels to an mb100? Decent reduction in weight?

I love the look of em

It would be a Waste of time fitting something you cant get decent tyres for.
But Depends on what look you want. Its your bike your style
There is a couple of sites that give bearing cup size for fork conversions
One is ohio cafe racer http://www.ohiocaferacers.com/OCRStemSizes.pdf
the other is https://www.allballsracing.com/index.php/forkconversion
Use mb5 for the bearing size (all small hondas are the same)
Do a complete front end with at least 32-35mm forks and wheels 17 inch sizes to suit.
Any wheel in decent size will be heavier than std.

[flyingbrick]

Thanks mate. Do many people get wider aluminium rims laced into place?

[husaberg]

Thanks mate. Do many people get wider aluminium rims laced into place?

Yip some like F5dave used XL250 rims alloy 2.15x17 on buckets.
if you wait and watch on trademe you can get 3.5x17 rims off torpedo 7 for down to $125-140 esp at Xmas
there was a DR250 rear wheel on TM for !00 offer him 80$ its been on their for a year. they have 2.15x17
Lacing it will cost though you need to know what you are doing try push bike shop but let him srip it so he can measure the off set first.
Something like a CB250RS front forks and Wheels would suit or GL145.
But there is nothing wrong with the rear brake on a MB100 is basically the same as any honda rear drum up to XR500.
But any disc front end with fork is better than a MB100 front end.
On the net there is a Nicie Aussie champ wnining bike that was a H100/MB100
https://www.nmrm.com.au/racing-in-bathurst/36-museum/our-bikes/97-honda-h100-qbucketq-racer.html
here is a list of forks to go with the list of bearings
http://www.perosoft.org/yamaha/Motorcycle-fork-tube-sizes.pdf

or you could find a MB5 fit the MB100 engine and go from their but though they look cooler they are spindly and not common but the MB100 fits with min mods and it can be registered with cheap 50cc reg.
You could likely do the same with a NS50 and a NS1

[flyingbrick]

Thanks tons for all the info mate.

Loving my bike!! Did around 500km within 4 days of buying the thing. Its not that fast but huge amounts of fun.

Have found rd350 reed blocks on ali express for cheaper than a genuine used one.. may place an order soon.

[husaberg]

Thanks tons for all the info mate.

Loving my bike!! Did around 500km within 4 days of buying the thing. Its not that fast but huge amounts of fun.

Have found rd350 reed blocks on ali express for cheaper than a genuine used one.. may place an order soon.
A cr80-85 one is a bolt on with only port work needed. We used RD ones because CR ones were against the rules.
RD ones need two holes redrilled plus two slotted with a chainsaw file or similar.
The tiny std carb and exhaust are a bigger restriction than the ports or reed.
The rd rubber needs the same mods plus a lttle trim of the inside ears but will allow a 28mm carb

[speedpro]

Standard reed is good for at least 19.9hp with a RD350 carb rubber and 28mm carb bunged on top. Standard transfers are good for 22+hp. I used an RD350 reed and it worked great. Replace the petals with a carbon fibre single petal each side and fill the inside of the reed with devcon to guide the air from the carb to the reeds.

[husaberg]

Standard reed is good for at least 19.9hp with a RD350 carb rubber and 28mm carb bunged on top. Standard transfers are good for 22+hp. I used an RD350 reed and it worked great. Replace the petals with a carbon fibre single petal each side and fill the inside of the reed with devcon to guide the air from the carb to the reeds.


Thanks tons for all the info mate.

Loving my bike!! Did around 500km within 4 days of buying the thing. Its not that fast but huge amounts of fun.

Have found rd350 reed blocks on ali express for cheaper than a genuine used one.. may place an order soon.

I have a spare late CR85 reed here if you can con Mike into fitting it for you (i will send it gratis to mike) I LIKELY HAVE RD ONES AS WELL ;)
I am pretty sure i have a CR85 28mm carb to.
I think i might have a 6 speed box left also that i would exchange for something of similar value ie yam forks or something for a current project.
But same condition that it gets fitted and used.

[flyingbrick]

I have a spare late CR85 reed here if you can con Mike into fitting it for you (i will send it gratis to mike) I LIKELY HAVE RD ONES AS WELL ;)
I am pretty sure i have a CR85 28mm carb to.
I think i might have a 6 speed box left also that i would exchange for something of similar value ie yam forks or something for a current project.
But same condition that it gets fitted and used.

Sounds great mate, lets do this!!!

I'm a fitter turner by trade (project manager now) so with a little instruction can probably make CR fit. I have a cheap new 28mm carb here but definately want to go with whatever is easiest in terms of fitment.

Not much I can help with in terms of exchange- will have to be cash :-D

Where are ya based?

Edit- jusut noticed the other replies to this thread. FArkin good information, thanks everyone.

What you chaps talk about HP, is this wheel hp? So 20hp is likely more than double the factory 11(engine)hp?!!!!!

[husaberg]

Sounds great mate, lets do this!!!

Is there any performance difference between CR85 and RD reeds? I'm a fitter turner by trade (project manager now) so with a little instruction can probably make it fit. I have a cheap new 28mm carb here but definately what to go with whatever is easiest in terms of fitment.

Not much I can help with in terms of exchange- will have to be cash :-D

Where are ya based?
Other island left side
You will have to get Mike Spedpro on board.
Two stroke tuning and MB gearboxs conversions are a little harder than they look. I am sure you possess the skills but mike has vast experience
My misses would spend cash but is currently unable to spend bike parts
I think i have a tacho here if yours doesnt as well.

[flyingbrick]

No problem mate. We can sort something out. You guys on facebook?

[husaberg]

I found this
ESP made for the MB series i dont know what a RD inlet ges for new but all the second hand ones will be hard as steel and cracking by now.
https://www.jmpbparts.com/manifold-26-28mm-malossi-honda-mb-mt.html
$66 NZD plus post
339332

Okay New RD ones are $48 nzd ON TRADEME
https://www.trademe.co.nz/motors/motorbikes/parts-for-sale/engine-components/listing-1819818299.htm?rsqid=c2eb1561cf124f558c1adec65f13b 642

339336
You could make one like dave Did
339334339335



Standard reed is good for at least 19.9hp with a RD350 carb rubber and 28mm carb bunged on top. Standard transfers are good for 22+hp. I used an RD350 reed and it worked great. Replace the petals with a carbon fibre single petal each side and fill the inside of the reed with devcon to guide the air from the carb to the reeds.
For mike this is what a late cr80-85 reed looks like save a bit of trouble modding a RD inlet to two reed.
339337339338
They are also ever so slightly slightly asymmetrical.

[F5 Dave]

MB50 gearboxes fit right in, no mods. You won't get that sort of power increase without increasing the revs to race levels. The crank will die if you don't rebuild it and ask power from it but are reliable when built with decent parts. It will then need a pipe. Chassis mods like disc front will require LVV certificate.

As a road bike is this really worth it?

An RZ350 will be much more fun if you can afford it and still make the right sort of noises.

[flyingbrick]

ARgh.. lost what i typed out.

Thanks again everyone.

You are right Dave, bigger bike is better value. Its on the cards at some stage- I have had faster previously and my dream bike is probably an RS250 :-D

The guys I ride with all have very small capacity bikes- It would actually be less fun having something that got from a-b without a screaming panic. At this stage its quicker than a px200 vespa and a few a100's (and similar yamaha thing) :headbang: but those bikes are always getting faster.

Actually used one of your old posts (in another thread) to choose spark plugs earlier today, Dave.

[Autech]

ARgh.. lost what i typed out.

Thanks again everyone.

You are right Dave, bigger bike is better value. Its on the cards at some stage- I have had faster previously and my dream bike is probably an RS250 :-D

The guys I ride with all have very small capacity bikes- It would actually be less fun having something that got from a-b without a screaming panic. At this stage its quicker than a px200 vespa and a few a100's (and similar yamaha thing) :headbang: but those bikes are always getting faster.

Actually used one of your old posts (in another thread) to choose spark plugs earlier today, Dave.

Who's your crew? Should jump on my wifes GN250 (if I ever get it running right) and join yas for a blat.

[F5 Dave]

Look I used to ride a lot of ks on an RG50 despite an 1100 in the garage.
I did 6 cold kiwis on one. Small bikes are cool.

And there's a fair few spare MB parts in case of a racing return.
But,

[flyingbrick]

Who's your crew? Should jump on my wifes GN250 (if I ever get it running right) and join yas for a blat.

I'll flick you a PM bro. Going out to Kawhia tomorrow i think.

[flyingbrick]

So where do i find a quality 57mm big bore kit and what kinda capacity does that take things out to?

[husaberg]

So where do i find a quality 57mm big bore kit and what kinda capacity does that take things out to?
the 57 mm kit i linked last page
or maybe not
http://www.tvd-parts.nl/010480/en
http://www.50cc.eu/en/product.asp?P=1782_cylinder-kit-honda-honda-mb8/mt8-eurocilindro-57mm
https://www.vsmotoparts.com/athena-cilinder-125cc-honda-mb8-mt80
https://www.google.co.nz/search?q=mb8+57mm&rlz=1C1GGRV_enNZ810NZ811&tbm=isch&tbo=u&source=univ&sa=X&ved=2ahUKEwjPt4KYlrjeAhVGAHIKHcG_CLcQsAR6BAgAEAE&biw=1920&bih=920#imgrc=o0GFW0FQI-1FpM:

i have no idea why its referred to as a 115cc kit by my maths it would be over 125cc

[F5 Dave]

Malcom bought one. Not sure if he used it but wasn't super happy with it, at least for a racing bassis. From memory the transfers were a little thin.

[flyingbrick]

good quality new condition motorcycle RD350 RXZ YZ125 DT175 intake reed valve for yamaha 175cc DT 175 air system spare parts
https://s.click.aliexpress.com/e/caVeL5gT


Cheap!

[husaberg]

good quality new condition motorcycle RD350 RXZ YZ125 DT175 intake reed valve for yamaha 175cc DT 175 air system spare parts
https://s.click.aliexpress.com/e/caVeL5gT


Cheap!
Remember I will send yo one for free Dude cheaper........
As for the pipe make one yourself.
20 Gauge mild steel.
go into mico metals and get some 75mm or 100mm thin wall irrigation pipe for the slenncer. Or free if you know a market gardener.
I am happy to do a quick and nasty design for a stock cylinder and big carb and reed combo. But mikes will have access to better.
Almost anything will be better than stock.
But as i said Try and convince Speedpro to do a cylinder for you to suit he has vast experience in what works and what doesnt. Its very easy for someone not experienced to make it go slower.
Mikes basic combo would double your power out put to 20 hp or a bit more.
His full house race bike was over 3x stock.

[husaberg]

Malcom bought one. Not sure if he used it but wasn't super happy with it, at least for a racing bassis. From memory the transfers were a little thin.
Was it plated Dave?
From what i have seen in the pics i agree with transfer shape and width.
But theres no replacement for displacement as the yanks say.
Also i doubt there is many left in the worldand i cant see anymore getting made but pistons are available and single ring.
So if he wants one i would suggest he buys one now before they all disappear.
Also the durations from what has been written std are incredibly mild i think more cooking than the H100 even.
I have not seen Koba post for ages is he sprogging or something..


bump.

[speedpro]

KT100 bits go straight in. Pistons start at 52mm and are single ring. You could even have the crank rebuilt using all KT100 bits. Not sure on availability due to changes in karting. The deck height will need adjusting. If you lean on it even a little bit with compression and revs you will need an adjustable ignition. Ignitech is definitely the go and can obviously be transferred to the next bike if required. My Ignitech is now in my 4T scooter. An Ignitech system is a very good investment. Get a 2 channel DC CDI system. I only use one channel but could double them up but haven't seen the need. A built crank should be good for 14,000rpm but 12,000 should be plenty on the street.

[F5 Dave]

Don't think it was plated, wasn't that long ago. He's running wgtn racing now in between being overseas.

Yeah KT piston skim the barrel top as shorter but cheap and great quality.

[flyingbrick]

What do people here use for image hosting these days?

[husaberg]

What do people here use for image hosting these days?
Post them direct on the KB server from your device.
Not sure if you have enough posts to do that yet maybe.
Nah you should

[flyingbrick]

If this works you will see my new seat.

[flyingbrick]

So good. Just needs a little more power.

[flyingbrick]

Hi everyone! Hope you are all enjoying summer so far :-D.

I managed to purchase numerous parts and a workshop manual for this thing and still racking up kms wherever possible.

A few questions-

Every time i ride it my clutch feels like the plates are initially stuck together and then afterwards the clutch seems to slip.

Before i strip it down to inspect and measure plates and basket- are there any recommended suppliers of new parts?

Also, do bar end weights do what they promise and reduce vibrations? Im tired of having (what i like to call) weed eater hands. Lol.

Best oil for gearbox?

Cheers :-D

[husaberg]

Hi everyone! Hope you are all enjoying summer so far :-D.

I managed to purchase numerous parts and a workshop manual for this thing and still racking up kms wherever possible.

A few questions-

Every time i ride it my clutch feels like the plates are initially stuck together and then afterwards the clutch seems to slip.

Before i strip it down to inspect and measure plates and basket- are there any recommended suppliers of new parts?

Also, do bar end weights do what they promise and reduce vibrations? Im tired of having (what i like to call) weed eater hands. Lol.

Best oil for gearbox?

Cheers :-D

Sticking plates is a common Honda malady
Kick it over with the clutch pulled.That will generally free it.
I used to use Mobil 1 but its likely different now with fiction modifiers etc not suited to bike clutches
Honda used to recommend Castrol GP.
The Honda MB100 clutch plates are the same on pretty much all small Hondas just the number of plates varies.
If its slipping on a std MB you might not have enough free-board on the clutch or the plates are just worn.
If it vibrates your mounts are likely loose or slogged our wider. or its not shimmed correctly.
N ewer grips that are more rubbery might help.weights can help with tingling vibes as its a resonance thing so could changing the bar design or shape.
If you do the clutch check on the timing of the balance shaft at the same time just to be sure..
Clutch plates on the CR80-85 fit and are supposed to be better material but any accessory part shop will have plates anyway.
The springs tend to sag with age as well. EBC used to do stronger springs i never used them.

[F5 Dave]

You can file down the pillars to preload the springs a little. Or add another plate but requires machining and not really required until over 20hp.

[flyingbrick]

Thanks you two.

Just ordered a pair of new shocks for the back as these are shagged- next mission is re-wiring the thing to full wave 12v.

Also bought a spare rear swing arm to lengthen a couple of inches (purely for looks, nothing too crazy) and husaberg steered me into a great deal on some carbs.

@husaberg have you managed to find any forks yet? I found a 6 speed box for $300 but probably couldnt get that much past the wife at the moment.

[husaberg]

Thanks you two.

Just ordered a pair of new shocks for the back as these are shagged- next mission is re-wiring the thing to full wave 12v.

Also bought a spare rear swing arm to lengthen a couple of inches (purely for looks, nothing too crazy) and husaberg steered me into a great deal on some carbs.

@husaberg have you managed to find any forks yet? I found a 6 speed box for $300 but probably couldnt get that much past the wife at the moment.

300 seems fair enough,but if are in the right place you can get complete bikes for that with spares its the luck of the draw,
Have you have you tried Ebay for a 1980-1982 Cr80 (Red engine gearbox)
they are better ratios than the MB5.

[Autech]

Thanks you two.

Just ordered a pair of new shocks for the back as these are shagged- next mission is re-wiring the thing to full wave 12v.

Also bought a spare rear swing arm to lengthen a couple of inches (purely for looks, nothing too crazy) and husaberg steered me into a great deal on some carbs.

@husaberg have you managed to find any forks yet? I found a 6 speed box for $300 but probably couldnt get that much past the wife at the moment.Guy that bought some fairings off me today mentioned he has a MB100. Want me to ask him if he has any spares lying around he could on sell?

Sent from my SM-A730F using Tapatalk

[flyingbrick]

Dont really need anything but ask him anyway thanks mate!

I tightened my head bolts.. they were so loose that after turning off the bike you could see oily air bubbling out from between the head and cylinder and cylinder and case!

Still bubbles from cylinder and head (will need new gasket) but shes gained over 10kph!!! Top speed on open road now 120ish

[F5 Dave]

Came across one of these . This might perk it up.

[TZ350]

Came across one of these . This might perk it up.

It would perk me up..... yes sir.

[husaberg]

https://www.youtube.com/watch?v=_HYJ2-4oGp4
A bit more realistic
even with the gearbox speed up its going to be a weak link

[F5 Dave]

Check out the honey container in the background.

[TZ350]

.
Taranaki ...... :2thumbsup

[flyingbrick]

One day i might go through these pages and compile an actual manual on mb performance.. getting sick of going backward and forward through this and ese threads searching lol.

Will making my head seal with no gasket make a noticable increase in compression?

Do people space up mb cylinders to raise the ports? (And machine top of cylinder)


Just easy to complete tasks that I've read about online

[F5 Dave]

Just throwing away the gasket and using some Loctite naster gasket will seal just fine. That will reduce the squish and increase the compression ratio. But you really must measure both to be sure you don't go too close or too high.

From this point you will need to consider a crank rebuild as more revs are more stress will call time on old parts.

[flyingbrick]

Thanks mate. Appreciate it.

If i could swing another 600 past the wife (the cost of initial bike purchase again) id have a spare engine to build and a 6 speed box.. doh.

What do i have here to sell....

[flyingbrick]

I'll slip some solder in the plug hole to measure squish.. saw that on a youtube channel,

would you consider that small increase in CR Worthy of a jet change? I know nothing about anything so learning lots as i go

[flyingbrick]

Sorry about flooding with posts. Do these photos tell anyone anything worth knowing?

[speedpro]

The head tells me either the chamber and squish band is not concentric with the cylinder or someone has machined it on the piss. There is also signs of blowby on the gasket surface, more obvious on the cylinder. That clean region in the squish says the piston is getting real close. That will need to be sorted out so it is even all around before you remove the gasket. Once you start getting the compression up over 12:1 or so even very small changes in chamber volume have a big effect on the compression ratio. As Dave said things need to be measured carefully. With the less than ideal porting and pipe you could probably go to something close to 14:1, depending on what else you do.

[F5 Dave]

And be on gas 95 min.

[flyingbrick]

Thanks all. According to the last owner this thing hasnt been worked on since purchased in 91 and one lady owner before him :lol: so could be factory machining?

I have cleaned everything up and will re assemble with the same gasket to get me riding again.

Will throw some master gasket in there to try stop the leaks and will use a torque wrench. Are factoey tq specs good? I have it listed in manual as just 14-17 ft-lb...seems low?

[flyingbrick]

Also.. the intake and side ports are lower than pistol at bottom dead center.

Could i move gasket to bottom of cylinder? This would raise ports (i hear this is good) but keep squish up top the same?

Sorry if a rediculious question

[flyingbrick]

Took one squish reading. 1.04mm. enough to tell me i need to keep the gasket haha.

Im surprised how close it is already!

[F5 Dave]

Yeah that's not std I'd bet.

[Ocean1]

I have cleaned everything up and will re assemble with the same gasket to get me riding again.

Will throw some master gasket in there to try stop the leaks and will use a torque wrench. Are factoey tq specs good? I have it listed in manual as just 14-17 ft-lb...seems low?

I found straight silicone is better than master gasket with a used head gasket. Degrease everything and just wipe a thin smear over both sides. Seals up the minor imperfections usually dealt with by the coatings they put on a new gasket, and it's good for the high temperatures.

And whatever torque is in the book is better than any guess you'll make, so unless someone's got a bunch of empirical data to the contrary why would you fuck with it?

[flyingbrick]

Thanks ocean1.

Have seen many times over the years experienced people specifying different torque values over factory suggestions.

Its all together now and torqued to factory specs in the suggested order (although i did take it to full torque in a few passes)

I used a smear of 518 as ita supposedly better on aluminium than the 515 i also have. I hate silicone and wish i didnt even have to use it in the bathroom.

Want to dive head first into a full rebuild and porting but like riding it too much :-D

[flyingbrick]

Oops double post

[TZ350]

Do people space up mb cylinders to raise the ports? (And machine top of cylinder)

1. Space the cylinder so the transfers are in the right place.
2. File the exhaust port so its timing and width are in the right place.
3. Boysen port the inlet and cut the piston skirt so the inlet timing is in the right place.
4. machine the cylinder to get the deck height in the right place.
5. "O" ring the top of the cylinder, a 2mm thickness Viton "O" ring makes a great head gasket.
6. Skim the head and angle the squish to match the piston.
7. CC the head.
8. 0.6mm squish clearance, checking with solder I go for 0.8 and figure it will be 0.6. Crank is bendy.
9. Don't open up the exhaust duct, they are usually to big from stock.
10 The exhaust duct at the exhaust flange should be 95% of the area of the single exhaust port. much less for triple exhaust ports.

[F5 Dave]

11. Case reed it.
12. Water cool it.
13. Triple port it.

Just me? Sorry .

[TZ350]

.
14 Rotary Valve
15 NSR H2O cylinder ............................. :laugh:

[flyingbrick]

300 seems fair enough,but if are in the right place you can get complete bikes for that with spares its the luck of the draw,
Have you have you tried Ebay for a 1980-1982 Cr80 (Red engine gearbox)
they are better ratios than the MB5.

Have found complete '99 cr80 transmission for $180. Will this fit and worth buying or are the ratios too wrong?

[husaberg]

Have found complete '99 cr80 transmission for $180. Will this fit and worth buying or are the ratios too wrong?

Never tried
the one we know this fits is the 1980 -1981 cr80.

[F5 Dave]

In 20 years one would expect they would have made the cases smaller.

[husaberg]

In 20 years one would expect they would have made the cases smaller.

I have a late cr80 here the gear center spacing is about the same 75mm ish.
The selctors set up are different
the primary gears are much narrower though, clutch about the same.

[flyingbrick]

@husaberg

Who would you recommend to supply carb kits for this pair of mikunis? Damn nice looking items- feel like much higher quality than the Chinese ones I have.

[husaberg]

@husaberg

Who would you recommend to supply carb kits for this pair of mikunis? Damn nice looking items- feel like much higher quality than the Chinese ones I have.
oe only likely although RM80's had a similar carb but not downdraft.
https://www.mikunioz.com/flat-side-carbs-non-pump/tm28-parts/?v=8e3eb2c69a18
https://www.ebay.com/itm/Suzuki-RM80-1986-1995-Carb-Carburetor-Repair-Kit-RM-80-/263033723978?fits=Model%3ARM80

NZ
http://motozone.nz/all-balls-carburetor-rebuild-kit
B261115
CARBURETOR REBUILD KIT RM80 1986-95 - INDENT Ask a question about this item SOLD OUT $51.15


The only thing that wears out is the float valve. and Needle jet.
both are common mikuni parts as designated by their VM part number.
ps the Choke off the MB100 fits the Mikuni.
You might want to drill out the fuel tap or preferably fit a larger one on that MB before you tune it as well.

[flyingbrick]

As usual.. thanks tons for the amazing advice mate. Very cool.

Very happy about the choke situation as didnt want to stuff around with an extra cable.

I guess its time to go pre-mix because the oil pump to throttle position is going to be pretty hard to get right with new carb.

@husaberg how can i get this rd reed assembly off ya? :-D

[husaberg]

As usual.. thanks tons for the amazing advice mate. Very cool.

Very happy about the choke situation as didnt want to stuff around with an extra cable.

I guess its time to go pre-mix because the oil pump to throttle position is going to be pretty hard to get right with new carb.

@husaberg how can i get this rd reed assembly off ya? :-D
i will send it up pretty sure i have your Address?
I have couriers bags i will see what else i have kicking about i know i have a cylinder spacer.

[husaberg]

Thanks mate. Do many people get wider aluminium rims laced into place?

https://www.trademe.co.nz/motors/motorbikes/parts-for-sale/wrecking-bikes/listing-2034687034.htm?rsqid=rmlms-0defb714250148e58e943a40e30cd26b

[flyingbrick]

Hi everyone, hope you are all well.

I tried getting my MB to cold kiwi :facepalm: put a hole in the piston.

Darn thing had been so reliable too, would have been a real novelty!!

So now i'm on the hunt for a new piston (and will put on my bigger reed assembly, intake and carb etc while im there)

So where is a good source for pistons? Getting a bit frustrated with availability of old bike parts lol

I even bought a Yamaha wr200 engine to shoehorn in, figured it would be a nice boost in power and the package is essentially the same size. Alas it was not to be- the motors bottom end is full of water and stuck solid. :laugh:

[husaberg]

Hi everyone, hope you are all well.

I tried getting my MB to cold kiwi :facepalm: put a hole in the piston.

Darn thing had been so reliable too, would have been a real novelty!!

So now i'm on the hunt for a new piston (and will put on my bigger reed assembly, intake and carb etc while im there)

So where is a good source for pistons? Getting a bit frustrated with availability of old bike parts lol

I even bought a Yamaha wr200 engine to shoehorn in, figured it would be a nice boost in power and the package is essentially the same size. Alas it was not to be- the motors bottom end is full of water and stuck solid. :laugh:

TKRJ or a
Strike in 52mm but as they are single ring they will need rings more regular. but come in tiny increments thus will never need rebores as hone to size.
What plug were you running as it should have nothing lower in number than a NKG"8".
KT100S
http://www.strikeproducts.com.au/pistons.asp

(NOT KT100J)

[F5 Dave]

I took my RG50 to cold kiwi. From Wellington. 6 times. Leaving 1100 in the garage.

Was a big rally in the 90s.

[flyingbrick]

Thanks all. Will check plug. I had changed it right before the ride but it should have been good.

Question, do you use the spring loaded 3 stone hones on this kind of thing? And then measure and tell strike what the finished size is so that they can supply the right piston?

Is the ledge top and bottom of the reed valve pocket there for any particular reason? Looks like it could be chamfered down significantly to increase flow?

[F5 Dave]

Think about flow out of the reeds. Actually it is pretty raw in that area.

You need a proper hone not one of those spindly things else damage can occur. They look like a barrel with a dial to increase size.

[husaberg]

Thanks all. Will check plug. I had changed it right before the ride but it should have been good.

Question, do you use the spring loaded 3 stone hones on this kind of thing? And then measure and tell strike what the finished size is so that they can supply the right piston?

Is the ledge top and bottom of the reed valve pocket there for any particular reason? Looks like it could be chamfered down significantly to increase flow?

He takes the cylinder to the local kart shop and tells them what he wants.;)
You are also best to find an Airooled CR80 cylinder and copy that

if you PM or text this guy
he might lend you one
https://www.kiwibiker.co.nz/forums/member.php/21379-Hilleye

[flyingbrick]

Thanks guys :-D i need to read this whole thread again.. iv forgotten stuff and its not good

Cheers

[koba]

I have not seen Koba post for ages is he sprogging or something..

Yes, it has been quite some time!

Life's been a bit hectic but not in sproggy ways.

So, I can offer a bit of an update on some things that may be of interest to people reading this thread.
I'll give the summary version and maybe get in to more detail later.


The standard MB
Rode one around for a while, loved it.
Put it on a Dyno with a decent rep for accuracy (Sketchy's dyno).
It told me 9 at the wheel, sounds about right.



Wheels/Tyres
I found a sticky tyre option for skinny 18's, PM me for details - Ideally in the next week or so as after that it might be a while until I log in again.



The MB125
I stumbled upon one of the big-bore kits linked earlier in this thread in a swap of some parts that didn't really go my way.
Once I got a chance to take a close look, I basically wrote it off as a race cylinder as it had what looked like very inadequate inlet area.

So, I had a road MB100 that I had going just for fun. It was OK for commuting on and quite usable, especially in slow traffic.
One day it spat the muffler baffle out the back of it on a 'high speed' (perfectly legal) run.
I re-made this and it worked fine for a long time.
Quite some time later, I was riding home at full throttle in top gear (over 90kph!) for about 5 minutes, I finally found out that baffle was a touch too restrictive.
It was quite an impressive blow-up with the ring-land ripped out of the side of the piston.

Anyway, I decided to put the 57mm kit on to the bottom end (now with a 6 speed).
I'm mocked this up earlier with an RD250 reed block and a Mikuni TM24 carb.
I found an old pipe, the RG400 one I started with.

I goes great!

I'm not sure of the horsepower, it's probably somewhere around 16-18.
I still haven't got the jetting just right, I need a different needle but can't find many of the advertised ones for sale.
It's running the standard MB ignition.
I used the standard cab manifold but modified it to take the 24mm carb with a 'frits style' manifold of 2 plates and an O ring.
I run an air filter, oil pump and kick start on this one.
Running the cylinder as low as I can I get 187deg on the exhaust which seems to be about right for a road bike.

I might nylon it up and give it a go on the track, would be interesting to compare this to the 'old nail'.

This ends up at a a touch over 126cc so legal in bucket terms if used with a 24mm carb and the now popular interpretation of the rules that a non-race aftermarket barrel is OK.



Where the liner ends
I got speedpro's old sidecar engine for a bottle of red wine in a bizzare trade.
It was so cheap as it was no longer useful for racing, being a 'little' over-sized.
Somewhere along the way it had blown up badly, the cylinder had been re-created and replaced, then blown up again and an oversized version added.
When I first encountered this one it was still in the sidecar but only being used for 'demo laps' with no other rigs to race against.
I guess somewhere there it didn't really matter that it ended up at a whopping 54.5mm.
I suspect the liner is paper thing though, it's actually got a bit of an odd pattern that may be the thin part.

This may end up in the road bike, just for fun.
Plenty of other things to do before then.




The Dirtbike MB100
I made a dirtbike version.
I won't tell the full story but it was crap, then OK, then crap. I ripped this up to make the 125 so may revisit it some time.



More soon, maybe :laugh:

[TZ350]

.
I love this thread! :2thumbsup